I Want Off This Rollercoaster

Last Thur I saw a number on the scale which put me in shock, 10st 5.5lbs/145.5lbs, only 0.5lbs away from my original goal I set myself just over 15 months ago. I just couldn't believe I was so close, then Friday I was back up to 146.5lbs and that's where I've stayed everyday since...
Granted I didn't have a great weekend, socialising and no exercise because I was still sick from the cold, but still. Yesterday however I went back to my usual double class at the gym and ate totally on plan. I was really sure that this morning I'd see a lower number on the scale but nope, same again...
I looked back at my weigh in records from about a month ago and it's looking like I could be coming up to the time when the scale usually starts bouncing for a week or so, before dropping again and taking another pound or two with it, but I'm not sure. I know it's a pattern that I seem to have found and that as long as I keep to my plan it will all work out in the long run, but still, it's driving me mad!!!
This fight I'm having with my scale really needs to stop. I still want to go back to weekly weigh ins only but there never seems to be a good time to do it. Right now I probably should do it so that the bouncing doesn't push me over the edge, but then again I'm scared that if I don't keep an eye on it it might bounce up and up even though I've not changed anything. I know it doesn't make sense, but I have this irrational fear that if I don't keep an eye on those scales they're going to revolt on me and start showing me higher numbers each weigh in, until I'm right back at 274lbs....
This pattern feels like I'm getting on a rollercoaster each month. There's the slow climb on the scale for several days/a week, the peak at the very top where my heart is in my mouth and I'm scared to death of what's going to happen next, then there's the sudden steep descent at the other side where I'm clinging on for dear life. I know the adrenaline rush after the descent is amazing, but really I wish I didn't have to get on this same ride each month....